ES2321926T3 - PROCESSES OF RADICAL POLYMERIZATION AND HALOGENATED POLYMERS. - Google Patents

Abstract

A method of preparing halogenated polymers by radical polymerization employing one or more ethylenically unsaturated monomers one at least of which is halogenated, molecular iodine and one or more free radical generators (diazo compounds, peroxides, dialkyldiphenylalkanes) by charging a reactor with at least a fraction of the three compounds, initiating the reaction and then introducing any balance of them. Independent claims are included for (1) halogenated polymers with a number average mol.wt. above 1.0x10 4> and a polydispersity index below 1.60, (2) for a method of preparing block copolymers of which at least one block is a halogenated polymer employing one or more ethylenically unsaturated monomers and one or more of the claimed halogenated polymers, (3) for block copolymers comprising one or more blocks of the claimed polymer, (4) for articles produced using one or more polymers prepared by the claimed method or claimed polymers .

Description

Radical polymerization processes and polymers halogenated

The present invention relates to processes of radical polymerization for the preparation of polymers of one or more chlorinated vinyl monomers and polymers for the preparation of which the polymerization processes object of it are particularly appropriate.

Halogenated polymers are prepared usually according to a radical polymerization process "classic" with the intervention of a halogenated monomer and a radical generating agent, which starts the growth of polymer chains According to this process, the time needed for a polymer chain grows to its final size is very brief, often less than 1 second. Also, along the polymerization, new chains are born, they grow, and they "die" almost immediately by recombination, by disproportionation or by radical transfer This "death" has a character random, statistical; it depends particularly on the polymerization temperature and medium viscosity. Of this mode, is obtained at the end of the polymerization halogenated polymer which has a statistically molecular mass distribution broad, whose polydispersity index (M_ {w} / M_ {n}) and M_ {z} / M_ {w} ratio usually have a value of at least 2. Such a process does not allow synthesizing polymers that have a narrow and controlled molecular mass distribution. It also does not allow the manufacture of block copolymers.

Certainly halogenated polymers prepared by the process mentioned above are appreciated because they present several interesting properties, particularly a high chemical resistance to alkalis and alcohols, as well as a high resistance to fire. More particularly, the polymers of vinyl chloride prepared by the process mentioned above they are appreciated because they can be relaxed if necessary by mix with plasticizers to manufacture flexible items such as artificial leathers

However, they have a certain number of points. weak, the main of which is that the numerous properties  of these polymers that depend on molecular mass are heterogeneous on a molecular scale, and may vary in fact from one polymer chain to another in the same way as the molecular mass itself. In particular, the presence of molecular mass polymer chains very low in the halogenated polymers of the technique anterior significantly degrades its thermal stability; the same it also significantly degrades the mechanical properties of articles made from them, in particular their resistance to breakage, abrasion and scratching. Conversely, the presence of polymer chains of very high molecular mass within these same halogenated polymers make their use more difficult (higher melt viscosity); it degrades too noticeably the mechanical properties of the items plasticized manufactured from them by default of gelation (imperfect mixture, at the molecular level, of the polymer halogenated and plasticizer), and other properties of these items such as transparency and surface finish.

Attempts have already been made to alleviate the disadvantages of "classic" radical polymerization process mentioned above and the weak points of halogenated resins prepared by this process developing a polymerization process described in the patent application EP 617 057 A. This process involves, in addition to the halogenated monomer and the radical generating agent involved in the classic process, a transfer agent organic iodine comprising at least one iodine atom attached to a primary carbon atom such as the 1-chloro-1-iodoethane.  The same "imitates", according to the terms used in this application, a radical "ideal" living polymerization process, in the sense that, as example 4 of the application shows of the above-mentioned patent, the number average molecular mass (or weight) of halogenated polymers synthesized by this process increases as the halogenated monomer polymerizes. Without However, the polydispersity index and the ratio M_ {z} / M_ {w} of the halogenated polymers synthesized by this process, although inferior to those of halogenated polymers prepared by the classic process, they are still high (for example, index of polydispersity greater than or equal to 1.70 for homopolymers of vinyl chloride), which shows that the process in question is strongly parasitized, just like the classic process, by transfer reactions and / or disproportionation and / or recombination, which interrupt or stop the growth of polymer chains. Another drawback of this process of the prior art lies in the need to use an agent of iodinated organic transfer, which is generally expensive and increases the cost price of the halogenated polymer.

Set up a polymerization process halogenated monomer radical more effective than the processes of prior art seemed to the experts a problem particularly difficult, since halogenated monomers, particularly vinyl chloride, vinyl fluoride, the vinylidene chloride and vinylidene fluoride, were considered intrinsically prone to transfer the radical activity of growing polymer chains on themselves (reactions of transfer on monomer) and / or on dead polymer chains (transfer reactions on polymer).

The present invention therefore has in first by object a radical polymerization process to the preparation of polymers of one or more vinyl monomers chlorinated that does not present the disadvantages of the processes of the prior technique while maintaining its advantages.

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For this purpose, the invention concerns a radical polymerization process for the preparation of polymers of one or more chlorinated monomers, which uses

(TO)

one or more ethylenically unsaturated monomers, at least one of the which is selected among vinyl monomers chlorinated,

(B)

iodine molecular, and

(C)

one or more radical generating agents selected from among the diazo compounds, peroxides and dialkyl diphenyl alkanes,

which comprises the stages according to which

(one)

be enter at least one fraction of each of the compounds (A), (B) and (C), and then

(2)

be reacts the reactor contents, introducing the eventual rest of each of the compounds (A), (B) and (C).

By polymers of one or more vinyl monomers chlorinated, it is intended to designate both homopolymers of chlorinated vinyl monomers such as the copolymers that form the chlorinated vinyl monomers with each other or with non-monomers halogenated These copolymers can be particularly statistical copolymers, block copolymers or copolymers of graft.

By halogenated monomer, the intention is of designating any ethylenically unsaturated monomer that It contains at least one halogen atom. As examples of monomers halogenated, halogenated vinyl monomers can be cited, halogenated styrenic monomers such as 4-Bromo-styrene, (meth) acrylic monomers  halogenated such as trifluoroethyl acrylate and dienes halogenated conjugates such as chloroprene.

Advantageously, at least 50 mol% and with preference at least 75 mol% of (A) are constituted by one or more ethylenically unsaturated monomers selected from among chlorinated vinyl monomers.

Halogenated monomers are preferably halogenated vinyl monomers. By halogenated vinyl monomers  it is intended to designate halogenated monomers monoethylenically unsaturated which are aliphatic and which have as their single heteroatom (s) one or more halogen atoms. As examples of halogenated vinyl monomers, there may be cited brominated vinyl monomers such as vinyl bromide, fluorinated vinyl monomers and vinyl monomers chlorinated

Particularly preferably, the halogenated monomers are selected from vinyl monomers chlorinated and fluorinated vinyl monomers.

By chlorinated vinyl monomers, you have the intention to designate monoethylenically chlorinated monomers unsaturated that are aliphatic and that have only one (s) heteroatoms (s) one or more chlorine atoms. As examples of chlorinated vinyl monomers can be cited vinyl monomers chlorinated whose number of chlorine atoms is 1, the monomers chlorinated vinyl whose number of chlorine atoms is 2, the trichlorethylene, 1,1,3-trichloropropene and tetrachlorethylene.

A first preferred family of monomers chlorinated vinyl is constituted by vinyl monomers chlorinated whose number of chlorine atoms is 1. As examples of chlorinated vinyl monomers whose number of chlorine atoms is 1, mention may be made of allyl chloride, crotyl chloride and, with A very particular mention, vinyl chloride.

A second preferred family of monomers chlorinated vinyl is constituted by vinyl monomers chlorinated whose number of chlorine atoms is 2. As examples of chlorinated vinyl monomers whose number of atoms is 2, can be cite 1,1-dichloropropene, the 1,3-dichloropropene, the 2,3-dichloropropene and, with a very mention in particular, vinylidene chloride.

By fluorinated vinyl monomers, you have the intention to designate monoethylenically fluorinated monomers unsaturated that are aliphatic and have only one (s) heteroatom (s) one or more fluorine atoms and, eventually In addition, one or more chlorine atoms. As examples of monomers fluorinated vinyl, there may be mentioned chlorotrifluoroethylene, the trifluoroethylene, perfluorinated vinyl monomers such as the tetrafluoroethylene and hexafluoropropylene, vinyl monomers fluorinated free of chlorine atoms and whose number of atoms of fluorine is 1, as well as fluorinated vinyl monomers free of chlorine atoms and whose number of fluorine atoms is 2.

A first preferred family of monomers fluorinated vinyl is constituted by vinyl monomers fluorinated free of chlorine atoms and whose number of atoms of fluorine is 1. As examples of such monomers, one can cite the allyl fluoride, and, with a very particular mention, the fluoride of vinyl.

A second preferred family of monomers fluorinated vinyl is constituted by vinyl monomers fluorinated free of chlorine atoms and whose number of atoms of fluorine is 2. As examples of such monomers, one can cite the 3,3,3-trifluoropropene and, with a very mention in particular, vinylidene fluoride.

According to a first preferred variant of the process of radical polymerization for the preparation of polymers of one or more chlorinated vinyl monomers according to the invention (variant (i)), (A) consists of a single ethylenically monomer unsaturated, which is a chlorinated vinyl monomer.

According to variant (i), advantageously at least 50 mol% of (A) and preferably 100% of (A) are introduced in the reactor in step (1).

According to a second preferred variant of the process of radical polymerization for the preparation of polymers of one or plus chlorinated vinyl monomers according to the invention (variant (ii)), (A) consists of several ethylenically monomers unsaturated, at least one of which is selected among the chlorinated vinyl monomers.

According to variant (ii), (A) may comprise possibly also one or more non-halogenated monomers.

If applicable, non-halogenated monomers are preferably selected from the styrenic monomers as styrene, (meth) acrylic monomers such as acrylate n-butyl and methyl methacrylate, esters vinyl such as vinyl acetate and olefinic monomers such as ethylene, propylene and butadiene.

According to variant (ii), advantageously at least 25 mol% of (A) and preferably at least 50 mol% of (A) they are introduced into the reactor in step (1). Advantageously, at minus 25 mol% and preferably 100% of the fraction of (A) introduced into the reactor in step (1), are constituted by one or more chlorinated vinyl monomers.

According to variant (ii), the respective orders of introduction in the reactor of the different monomers ethylenically unsaturated constituting (A), in stage (1) and in stage (2), can influence the ordering of the units recurring polymers of one or more vinyl monomers chlorinated produced by the reaction.

According to a first sub-variant preferred variant (ii) (sub-variant (ii.a)), the ethylenically unsaturated monomers that constitute (A) are introduced into the reactor in the same order of introduction.

The polymers of one or more vinyl monomers chlorinated prepared according to the sub-variant (ii.a) are advantageously statistical copolymers.

According to a second sub-variant preferred variant (ii) (sub-variant (ii.b)), one of the ethylenically unsaturated monomers that constitute (A) it is introduced into the reactor in step (1), being introduced into the reactor the or the other ethylenically unsaturated monomers that constitute (A) in stage (2), as many times as the number of ethylenically unsaturated monomers that constitute (A) minus 1, one after another, making only any new introduction of a ethylenically unsaturated monomer in the stage reactor (2) after the ethylenically unsaturated monomer (s) previously introduced into the reactor have each reacted in proportion of at least 50 mol%, particularly preferred at least 70 mol% and very particularly preferred at least 90 mol%.

The polymers of one or more vinyl monomers Chlorides prepared according to sub-variant (ii.b) are advantageously copolymers whose molecular structure is close, being however different, to which they present copolymers of ideal blocks (that is, without any interpenetration of the blocks)

According to a third sub-variant preferred variant (ii) (sub-variant (ii.c)), one of the ethylenically unsaturated monomers that constitute (A) [monomer (M1)] is introduced into the reactor in step (1), introducing all or a fraction of the other ethylenically unsaturated monomers constituting (A) [monomers (M2)] progressively in the reactor in step (2).

The eventual fraction of the monomer (s) (M2) that has not been progressively introduced into the reactor in step (2) is advantageously introduced into the reactor in the stage (one).

According to sub-variant (ii.c), the monomer (M2) or each of the monomers (M2), if any several of them, advantageously have a reactivity superior to the of the monomer (M_ {1}), that is to say the global speed at which the or each of the monomers (M2) is consumed by the reaction it is superior to that to which the monomer (M_ {1}) is consumed. Advantageously, in addition, the speed of introduction into the reactor of the monomer (M_ {2}) or, if there are several of them, of each of the monomers (M2), it is much higher the higher the reactivity of this or these monomers.

The polymers of one or more vinyl monomers Chlorides prepared according to sub-variant (ii.c) are advantageously copolymers whose molecular structure is close to the one presented by the ideal homogeneous copolymers (that is, those all whose polymer chains contain exactly the same molar fraction of repetitive structural units from each of the copolymerized monomers).

In the process of radical polymerization for preparation of polymers of one or more chlorinated vinyl monomers according to the invention, molecular iodine (B) can be introduced into the reactor as such or in the form of a precursor, which reacts in the reactor to release molecular iodine. As an example of such precursors, alkali metal iodides, such as potassium iodide, as long as the reactor comprises a phase Aqueous pH acid with hydrogen peroxide or an organic peroxide water soluble. Preferably, (B) is introduced as such.

The number of moles of (B) referred to the number of moles of (A) is at least advantageously 2.5.10-5, with preferably at least 5.10-5, and particularly preferred at least 10-4. In addition, the number of moles of (B) referred to the number of moles of (A) is advantageously at most 10-1 and preferably at most 10-2.

Advantageously, at least 50 mol% of (B), and more advantageously still 100% of (B), are introduced in the reactor before the duration of stage (2) has reached 2 hours, preferably before the duration of stage (2) reached 1 hour and very particularly preferred in the stage 1).

Diazo compounds, peroxides and dialkyl diphenyl alkanes selected in (C) may be usual.

As examples of diazo compounds, you can cite the acid 4,4'-azobis (4-cyanovaleric) (water soluble diazo compound) and azobisisobutyronitrile (oil soluble diazo compound).

As examples of peroxides, one can cite water-soluble peroxides such as ammonium persulfate and water oxygenated, and oil-soluble peroxides such as dialkyl peroxides, dialkyl peroxydicarbonates and peresters.

(C) is preferably oil soluble.

The number of moles of (C) referred to the number of moles of (B) is advantageously at least 1. In addition, the same applies advantageously at most 10, preferably at most 5.

Advantageously, at least 50 mol% of (C), and preferably 100% of (C) are introduced into the reactor in the stage 1).

In the process of radical polymerization for preparation of polymers of one or more chlorinated vinyl monomers according to the invention, they may eventually be introduced also in the reactor, in step (1) and / or in step (2),

(D) one or more complexes of a metal, in the oxidation state 0, or in a strictly oxidation state positive, selected among the transition metals, the lanthanides, actinides and metals of group IIIa, and of a ligand of this metal.

According to a first preferred embodiment of the radical polymerization process for the preparation of polymers of one or more chlorinated vinyl monomers according to the invention (embodiment (I)), is also introduced in the reactor, in stage (1) and / or in stage (2),

(D) one or more complexes of a metal, in the oxidation state 0 or in a strictly oxidation state positive, selected among the transition metals, the lanthanides, actinides and metals of group IIIa, and of a ligand of this metal.

As examples of metals in the state of oxidation 0, mention may be made in particular of Al (0), Cr (0),  Cu (0), Fe (0), Mg (0), Mo (0), Ni (0), Pb (0), Pd (0), Sm (0), W (0), and Zn (0).

As examples of metals in a state of strictly positive oxidation, can be cited particularly Ce (III), Cu (I), Cu (II), Fe (II), Fe (III), Ni (I), Rh (III), Rh (IV), Ru (III), Ru (IV), and Ti (IV). Metals in a state of oxidation strictly positive are advantageously introduced in the form of salts, by example in the form of chlorides, bromides, iodides or Tellurides

Preferred metals are Cu (0), Cu (I), Cu (II) and Ti (IV).

As examples of metal ligands above mentioned, particularly amine ligands can be cited as Bipyridine (Bpy) and the 1,1,4,7,10,10-hexamethyltriethylenetetramine ligands phosphorous such as triphenylphosphine (P (Ph) 3) and other ligands such as indeniLo, cyclopentadienyl (Cp), tris [2-aminoethyl] amine (TRAIN), the tris [2- (dimethylamino) ethyl] amine (Me6TREN) and acetylacetonate and butanolate anions (OBu) - where Bu designates an n-butyl group.

Preferred ligands are (OBu) -, Cp, Bpy, TRAIN and Me6TREN.

Examples of complexes can be cited in particular Cu (0) / Bpy, Cu (I) Cl / Bpy, Cu (I) Br / Bpy, Cu (I) I / Bpy ,
Cu (I) Cl / TREN, Cu (I) Cl / Me6TREN, Cu (II) Te / Bpy, Ti (IV) Cp 2 Cl 2 and Ti (IV) (OBu) 4. The complexes mentioned above have given very satisfactory results.

According to the embodiment (I), the number of moles of (D) referred to the number of moles of (B) is advantageously at least 10-2, preferably at least 10-1. In addition, the it is advantageously at most 10 2, preferably as maximum 10 1.

According to the embodiment (I), the number of moles of (C) referred to the number of moles of (B) is advantageously at most 1.4 and preferably at most 1.2.

According to a second preferred embodiment of the radical polymerization process for the preparation of polymers of one or more chlorinated vinyl monomers according to the invention (embodiment (II)), the content of the reactor, in stage (1) and stage (2), is free of a metal complex, in the oxidation state 0 or in an oxidation state strictly positive, selected among the metals of transition, lanthanides, actiniums, and group metals IIIa, and of a ligand of this metal.

According to the embodiment (II), the number of moles of (C) referred to the number of moles of (B) is advantageously at least 1.2 and preferably at least 1.4.

The radical polymerization process for preparation of polymers of one or more chlorinated vinyl monomers according to the invention it can be particularly a process of polymerization in solution, in solution-mass, in mass, in suspension, in microsuspension or in emulsion. So, in the radical polymerization process for the preparation of polymers of one or more chlorinated vinyl monomers according to the invention, is possible to eventually enter the reactor, in step (1) and / or in step (2), in addition to (A), (B), (C) and eventually (D), up to 1000% by weight based on the weight of (A), one or more ingredients usually used to polymerize vinyl monomers chlorinated, such as water, supercritical CO2, liquids of organic dispersion such as isopropanol, organic solvents such as benzene, tetrahydrofuran and cyclohexanone, agents of dispersion such as polyvinyl alcohols, and agents emulsifiers such as ammonium myristate (ingredients (U)).

To react the reactor contents according to step (2), means are used by which they are generated radicals in its bosom. For this purpose, you can particularly heat it, or expose it to light radiation intense

The temperature at which the reactor content is advantageously at least 30 ° C and with preferably at least 40 ° C. In addition, it is advantageously as maximum 200 ° C, and preferably maximum 120 ° C.

Advantageously, proceed to step (2) until that the chlorinated vinyl monomer (s), on the one hand, and the or any non-halogenated monomers, on the other hand, have reacted within certain limits.

Thus, one part, proceeds to step (2) until that have reacted with preference at least 10 mol% of the or of the chlorinated vinyl monomers introduced into the reactor. In addition, proceed to step (2) until they have reacted (i) maximum 70 mol% and particularly preferably as maximum 35 mol% of the chlorinated vinyl monomer (s) introduced into the reactor, if the monomer or ethylenically unsaturated introduced into the reactor are exclusively monomers chlorinated vinyl, and (ii) maximum 95 mol% of the one or more of the chlorinated vinyl monomers introduced into the reactor, if at least an ethylenically unsaturated monomer introduced into the reactor is a non-halogenated monomer, and then step (2) is terminated.

On the other hand, proceed to step (2) until that have reacted preferably at least 50 mol% of the or of any non-halogenated monomers introduced into the reactor. In addition, proceed to step (2) until they have preferably reacted at most 95 mol% of the one or more of the Any non-halogenated monomers introduced into the reactor.

To end stage (2), it is possible by example cool the reactor contents and / or introduce into it a potent inhibitor and / or extract from it the fraction of (A) that has not reacted, being able to perform these operations simultaneously or successively, in or outside the reactor.

Preferably, step (2) is terminated extracting from the reactor content the fraction of (A) that has not reacted (remoomerization treatment), if any after cooling the reactor contents and / or having introduced a potent inhibitory agent.

When the fraction of (A) that has not reacted has sufficient volatility, it will be extracted advantageously of the reactor contents by extracting it to empty.

The radical polymerization process for preparation of polymers of one or more chlorinated vinyl monomers according to the invention, it may eventually also comprise a stage, after the preceding stages, according to which the polymer of one or more chlorinated vinyl monomers of the content of the reactor (step (3)).

To isolate the polymer from one or more monomers chlorinated vinyl of the reactor contents, can be used, in addition to the treatment of decomomerization already exposed above, all separation methods known to experts in the art, particularly precipitation (in particularly when the polymer of one or more vinyl monomers chlorinated has been produced by a process in solution or solution-mass), tube filtration and drying in fluidized bed (particularly when the polymer of one or more chlorinated vinyl monomers have been produced by a process in suspension) and spray drying or coagulation (particularly when the polymer of one or more monomers Chlorinated vinyl has been produced by a process in emulsion or in microsuspension). These operations are advantageously performed outside. of the reactor.

The radical polymerization process for preparation of polymers of one or more chlorinated vinyl monomers according to the invention it is advantageously used to prepare the polymers of one or more chlorinated vinyl monomers according to the invention.

In addition, the present invention aims at a radical polymerization process for the preparation of block copolymers at least one of whose blocks is a block of polymer of one or more chlorinated vinyl monomers.

For this purpose, the invention concerns a radical polymerization process for the preparation of copolymers  of blocks at least one of whose blocks is a polymer block of one or more chlorinated vinyl monomers, which uses

(TO')

one or more ethylenically unsaturated monomers, and

(B ')

one or more polymers of one or more chlorinated vinyl monomers selected from the polymers prepared by the process such as described above and among those prepared in the course of a previous stage by the process referred to in this memory,

which comprises the stages according to which

(one')

be introduces into a reactor at least a fraction of (A ') and at least one fraction of (B '), and then

(2')

be reacts the contents of the reactor, introducing it time in it the eventual remainder of (A ') and the eventual remainder of (B ').

The radical polymerization process for Preparation of block copolymers according to the invention responds to the same features and preferences as described previously with regard to the polymerization process radical for the preparation of polymers of one or more monomers chlorinated vinyl, unless otherwise indicated or unless indicate otherwise.

The number of monomers ethylenically unsaturated constituting (A ') can be any. With preference, it is at most 2.

The ethylenically unsaturated monomers which constitute (A ') can be selected indifferently from halogenated monomers and non-halogenated monomers.

(B ') can be introduced into the reactor in any form, particularly in the form of a powder, of a dispersion, of an emulsion or of a solution, and after having been isolated or not from the content of the reactor in which it has been previously prepared (B ') is introduced into the reactor with preference after being isolated from the reactor contents in which it has been prepared previously.

The number of polymers of one or more monomers Chlorinated vinyls constituting (B ') is preferably 1.

Preferably, all of (B ') is it enters the reactor in step (1 ').

The weight of (B ') referred to the weight of (A') is advantageously at least 0.1 and preferably at least 0.5. Further, it is advantageously at most 4.

In the radical polymerization process according to the invention, they are also advantageously introduced into the reactor, in the stage (1 ') and / or in stage (2'), (C ') one or more agents radical generators selected from peroxides, the diazo compounds and dialkyl diphenylalkanes.

(C ') responds to the same characteristics and to the same preferences as (C), and this for any degree of preference.

In the process of radical polymerization for Preparation of block copolymers according to the invention is it is possible to also introduce further into the reactor, in the stage (1 ') and / or a stage (2'), (D ') one or more complexes of a metal, in the oxidation state 0 or in an oxidation state strictly positive, selected among the metals of transition, lanthanides, actinides and group metals IIIa, and of a ligand of this metal.

(D ') responds to the same characteristics and to the same preferences as (D), and this for any degree of preference.

The radical polymerization process for Preparation of block copolymers according to the invention is used advantageously to prepare the block copolymers according to the invention.

In addition, the present invention aims at polymers of one or more chlorinated vinyl monomers that do not have the disadvantages of halogenated polymers of the prior art while retaining its advantages and that they can be obtained particularly by the polymerization process radical for the preparation of polymers of one or more monomers chlorinated vinyl described above.

For this purpose, the invention relates to polymers of one or more chlorinated vinyl monomers having a number average molecular mass M n greater than 1.0.10 4 and a M_ {z} / M_ {w} ratio less than 1.65.

The molecular mass distribution of polymers of one or more chlorinated vinyl monomers according to the invention is usually determined by exclusion chromatography steric, as explicitly stated in Example 1 of present document

From the distribution of the masses Molecules thus obtained can be calculated in particular:

-

he number average molecular mass M_ {n} = \ Sigma Ni M_ {i} / \ Sigma N_ {i}, where N_ {i} is the number of moles of polymer mass molecular M_,

-

he weight average molecular mass M_ {w} = \ Sigma N_ {i} M_ {2} / \ Sigma N_ {i} M_ {i},

-

he medium molecular mass of higher order M_Z = E Ni M_ {3} / E N_ {M} {1} 2,

-

he polydispersity index M_ {w} / M_ {n},

-

the M_ {z} / M_ {w} ratio.

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The polymers of one or more vinyl monomers chlorinated according to the invention have a number average molecular mass M_ {n} preferably greater than 1.4.10 <4>, so particularly preferred greater than 1.8.10 4.

The polymers of one or more vinyl monomers chlorinated according to the invention have a relation M_ {z} / M_ {w} with preference less than 1.60.

In addition, polymers of one or more monomers chlorinated vinyl according to the invention have an index of polydispersity M_ {w} / M_ {n} advantageously less than 2.00.

The polymers of one or more vinyl monomers chlorinated according to the invention can be both homopolymers of chlorinated vinyl monomers as copolymers formed by monomers chlorinated vinyl with each other or with non-halogenated monomers. The they are preferably formed by at least 50 mol% of particularly preferred manner by at least 80 mol% and of very particularly preferred way for 100% vinyl monomers  chlorinated

As examples of monomer polymers chlorinated vinyl, monomer polymers can be cited chlorinated vinyl whose number of chlorine atoms is 1, the chlorinated vinyl monomer polymers whose number of atoms of Chlorine is 1, trichlorethylene polymers, polymers of 1,1,3-trichloropropene and polymers of tetrachlorethylene.

A first preferred family of polymers of chlorinated vinyl monomers is constituted by the polymers of chlorinated vinyl monomers whose number of chlorine atoms is 1. As an example of such polymers, the polymers of allyl chloride, polymers of crotyl chloride and, with a Very particular mention, vinyl chloride polymers.

Preferred vinyl chloride polymers they have a polydispersity index M_ {w} / M_ {n} advantageously less than 1.60, preferably less than 1.50 and so particularly preferred less than 1.45. In addition, the same they have a ratio M_ {z} / M_ {w} preferably less than 1.50.

A second preferred family of polymers of chlorinated vinyl monomers is constituted by the polymers of chlorinated vinyl monomers whose number of chlorine atoms is 2. As examples of such polymers, the polymers of 1,1-dichloropropene, from 1,3-dichloropropene, from 2,3-dichloropropene and, with a very mention in particular, polymers of vinylidene chloride.

The polymers of one or more vinyl monomers chlorinated according to the invention can be in the form of liquids or powders. Preferably, they are found in powder form

The polymers of one or more vinyl monomers chlorinated according to the invention have a whiteness measured with the MINOLTA® CR 200 chromimeter which is advantageously at least 80%, with preference at least 85%. The measurement of the MINOLTA® CR 200 chromimeter of the whiteness of the polymers of one or more vinyl monomers chlorinated according to the invention is carried out as set forth explicitly in Example 1 of this document.

In addition, the present invention aims at finally therefore block copolymers, at least one of whose blocks is a polymer block of one or more monomers chlorinated vinyl that have numerous advantages and that can be obtained particularly by the polymerization process radical for the preparation of block copolymers described previously.

For this purpose, the invention relates to block copolymers, at least one of whose blocks is a block of polymer of one or more chlorinated vinyl monomers identical to those polymers of one or more chlorinated vinyl monomers described above (block copolymers (CB1)).

It also concerns copolymers of blocks, at least one of whose blocks is a polymer block of one or more chlorinated vinyl monomers, which have a molecular mass numerical mean M_ {n} greater than 1.5.10 4, and an index of polydispersity M_ {w} / M_ {n} less than 1.60 (copolymers of blocks (CB2)).

For both block copolymers (CB1) as for block copolymers (CB2) according to the present invention, the weight of the polymer block or blocks of one or more chlorinated vinyl monomers is advantageously at least 1/10, with preference at least 1/3 of the weight of the block copolymers according to the invention. In addition, it is advantageously at most 4/5 of the weight of the block copolymers (CB1) and (CB2) according to the invention.

The block copolymers (CB1) and (CB2) according to the invention may optionally comprise one or Several blocks of non-halogenated polymer. As examples of such blocks, the homopolymer blocks of styrene and the statistical copolymer blocks of styrene and acrylonitrile. As a preference, the non-halogenated polymer block or blocks are homopolymer blocks

As examples of block copolymers according to the invention, the diblock copolymer composed of a block of a statistical copolymer of vinylidene chloride and the methyl acrylate and a block of a styrene homopolymer such as manufactured according to Example 7 of this document.

In addition, the present invention aims at polymer articles of one or more chlorinated vinyl monomers that do not have the disadvantages of polymer articles halogenated prior art, while retaining its advantages.

For this purpose, the invention relates to manufactured items that use one or more polymers selected from the polymers prepared by the processes such as described above and polymers such as have described above.

As examples of such articles, you can particularly cite the compact layers, the films, the sheets, plates and profiles, tubes and pipes, Putties and cell layers.

These items are usually manufactured from conventional way, applying known utilization techniques, such as calendering, extrusion, injection, coating, Spray application, soaking and molding.

The radical polymerization processes according to the invention present multiple advantages.

They have a very firm living character, although using halogenated monomers such as vinyl chloride, vinylidene chloride, vinyl fluoride and fluoride vinylidene, intrinsically considered as prone to transfer the radical activity of the polymer chains in growth on themselves (transfer reactions on monomer) and / or on dead polymer chains (reactions of polymer transfer).

Surprisingly, in the processes of radical polymerization according to the invention, an important number of polymer chains (re) are born at the beginning of polymerization and grow along it, without interruption or detention by parasitic transfer reactions and / or disproportionation and / or of recombination; the processes according to the invention differ so as to its reaction mechanism of the processes of known radical polymerization.

From a macroscopic point of view, this is translates by the fact that radical polymerization processes according to the invention they are such that in the course of the reaction, the mass Average molecular number (or weight) of polymers increases continuously when the fraction of chlorinated vinyl monomer that has reacted increases while it remains practically constant throughout a polymerization "classic" radical.

Another advantage of polymerization processes radical according to the invention, linked to the previous one, is that the growth of polymer chains of polymers of one or more Chlorinated vinyl monomers prepared by these processes can restart by reacting the polymers again, even after being isolated from its polymerization medium, with ethylenically unsaturated monomers, identical or different from those that had previously polymerized. In this way it is possible prepare block copolymers comprising at least one block of polymer of one or more chlorinated vinyl monomers. For him opposite, according to the radical polymerization process "classic", it is usually not possible to synthesize such copolymers

One last advantage of the processes of radical polymerization according to the invention is that they do not they need to use usually expensive raw materials such as iodinated organic transfer agents.

The polymers according to the invention retain all the advantageous characteristic properties of polymers halogenated prior art, particularly a resistance chemistry elevated to alkalis and alcohols, as well as a high resistance to fire.

They have a polydispersity index M_ {w} / M_ {n} and a relation M_ {z} / M_ {w} substantially reduced relative to the prior art polymers.

The polymers also have several other advantages in relation to its low polydispersity index. The main is that the numerous properties of these polymers that depend on the molecular mass present in molecular scale a improved homogeneity in relation to the halogenated polymers of the prior art

Due to the fact that they are chain free Very low molecular mass polymers, polymers of one or more chlorinated vinyl monomers according to the invention have a thermal stability superior to that of halogenated polymers of the prior art; In addition, items manufactured from these have mechanical properties, in particular resistance to breakage, abrasion and scratching, superior to those of articles made from the halogenated polymers of the prior art

Due to the fact that they are exempt of very high molecular mass polymer chains, the polymers of one or more chlorinated vinyl monomers according to the invention are used in a molten state more easily than polymers halogenated prior art; for the same reason, the plasticized articles manufactured from them gel better and therefore have mechanical properties, transparency and surface finish superior to those of manufactured items from the halogenated polymers of the prior art.

The following examples are intended to illustrate the invention without limiting, however, the scope of the same.

Example one

(According to invention)

In a 3.5 l reactor equipped with a stirrer and with double wrap, 2000 g of water are first introduced demineralized, 6 g of polyvinyl alcohol (agent dispersant), 1.5 g of molecular iodine and 1.5 g of peroxidicarbonate diethyl (radical generating agent). The reactor is closed and The reactor is then started. The vacuum is made in the reactor.

1000 g of chloride are introduced into the reactor vinyl.

The contents of the reactor are brought to 60 ° C. Be t_ {0} the moment when the reactor content temperature reaches 60 ° C. It is allowed to react.

At t0 + 3 hours 30 min, the reaction is stopped cooling the reactor contents as quickly as possible (mud) to room temperature.

The vinyl chloride sludge is not purified converted. Water is then removed by filtration at tube and fluidized bed drying. A powder of polyvinylchloride).

The fraction of vinyl chloride that is calculated is calculated. has reacted (conversion rate (f)), expressed in%, from of the dry matter content of the mud, determined in turn by gravimetry

The K number of the poly (chloride) is determined vinyl) according to ISO 1628-2.

It also determines the distribution of molecular masses of polyvinyl chloride by steric exclusion chromatography and whiteness of poly (vinyl chloride) by means of a Minoltat chromimeter CR® 200, as explained below.

Determination of the molecular mass distribution of a polymer

The distribution of the molecular masses of the polymer has been determined by means of a WATERS® Alliance 2692 chromatograph, equipped with a Shodex RI detector, model 2410, of WATERS® Styragel HR4, HR3 and HR2 columns in series, using LiBr dimethylformamide added as diluent at a concentration of 0.1 mol / liter, with a flow rate of 1 ml / min and a temperature of 40 ° C. Chromatography had been previously checked by means of poly (methyl methacrylate) standards, with Mark-Houwink's factors a = 0.770 and k = 9.45.10-5.

Determination of the whiteness of a polymer

A Minoltat CR® 200 chromimeter equipped with a xenon arc lamp has been placed under tension and the device has been stabilized. This has been configured in colors, multimedia mode, double channel 0, with source C as illuminating. The double channel 0 was then calibrated by means of an aluminum oxide standard plate. The polymer has been poured into a measuring cup provided for this purpose until slight overflow, then a MATOBEL® glass plate has been placed on it and compressed slightly so that the plate comes into contact with the edge of the bowl . Next, the chromimeter measuring head has been placed on the plate and 3 consecutive measurements (3 light flashes) of the Y, x, and CIELAB 1931 coordinates have been made. The average value has been taken and then calculated trichromatic component Z = xY ^ {2} / {2} and ^ - Y, and B = whiteness of az-b resin, having a value of 0.9 and a value of 1.085 b, where a and b Empirical coefficients previously determined experimentally in order to align the results obtained according to the present measurement technique with those obtained by means of a Photovolt® model 670 reflectometer.

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Example 2

(According to invention)

Proceed as in Example 1, except that the reaction has stopped at t_ {+} + 4 h (instead of t_ {0} + 3 h 30.

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Example 3

(According to invention)

Proceed as in Example 1, except that the reaction has stopped at t_ {+} + 5 h (instead of t_ {0} + 3 h 30.

The results of the different measures of Examples 1 to 3 are presented in Table 1.

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TABLE 1

one

Example 4

(Example comparative)

The distribution that the masses have been determined Molecules of commercial vinyl chloride homopolymers by medium of a WATERS® Alliance 2692 chromatograph, exactly in the same conditions as those applied in Examples 1 to 3.

The results of the measurements in Example 4 are presented in Table 2.

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TABLE 2

2

Example 5

(According to invention)

In a 4-liter reactor, equipped with a double wrap and a turbine-type agitator that rotates to 880 revolutions / minute, 2429 g of water have been successively introduced demineralized, a dispersing agent of methyl hydroxypropyl cellulose at a rate of 0.04 g per 100 g of monomer and 4.1 g (0.016 mol) of molecular iodine. The void has been made. They have introduced 13.4 g of tert-amyl perpivalate. After waiting 5 minutes, they have been loaded successively in the reactor 609 g (4.06 mol) of hexafluoropropylene and 644 g (10.06 moles) of vinylidene fluoride. It has warmed progressively the reactor contents until it has reached the temperature step of 60ºC. Have been injected progressively 614 g (9.59 moles) of vinylidene fluoride in the reactor, in order to keep the constant pressure in it, at a value 120 bar Then it has been let down gradually the pressure in the reactor, until it has reached 100 bar. It has been  then heated the reactor contents to 65 ° C. When the pressure in the reactor it has reached 60 bar, namely 597 minutes after having reached the temperature step of 60ºC, it has degassed the aqueous suspension (reducing the pressure to atmospheric pressure). Then the copolymer has been collected by filtration and then the same has been put back in suspension in clean water in a container with stirring. After of a wash cycle, the polymer has dried in the oven until constant weight

The weight fraction of hexafluoropropylene and vinylidene fluoride that has been consumed globally by the reaction: this has been 67%.

The distribution has also been determined of the molecular masses of the copolymer thus prepared by means of a WATERS® Alliance 2692 chromatograph, exactly in the same conditions that those applied in Examples 1 to 3. Have been obtained:

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M_{w} = 13,0.10^{4},

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M_{z} = 20,6.10^{4},

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M_{w}/M_{n} = 1,69

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y

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M_{z}/M_{w} = 1,58.M_ {n} = 7.7.10 <4>,

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M_ {w} = 13.0.10 4,

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M_Z = 20.6.104,

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M_ {w} / M_ {n} = 1.69

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Y

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M_ {z} / M_ {w} = 1.58.

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Example 6

(Example comparative)

It has been proceeded as in Example 5 except that Iodine has not been introduced into the reactor.

The pressure in the reactor has reached 60 bar 261 minutes after reaching the temperature step of 60 ° C

The weight fraction of hexafluoropropylene and vinylidene fluoride that has been consumed globally by the reaction: this has been 73%.

The distribution has also been determined of the molecular masses of the copolymer thus prepared by means of a WATERS® Alliance 2692 chromatograph, exactly in the same Conditions applied in Example 5. The following have been obtained:

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M_{w} = 20,9.10^{4},

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M_{z} = 41,4.10^{4},

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M_{w}/M_{n} = 2,20

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y

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M_{z}/M_{w} = 1,98.M_ {n} = 9.5.10 4,

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M_ {w} = 20.9.10 4,

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M_Z = 41.4.104,

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M_ {w} / M_ {n} = 2.20

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Y

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M_ {z} / M_ {w} = 1.98.

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Example 7

(According to invention)

The vacuum is made in a 300 glass reactor ml. A first solution composed of 64.8 g of vinylidene chloride, 14.4 g of methyl acrylate, 1.006 of molecular iodine and 88 g of benzene, and then a second solution composed of 0.975 g of azobisisobutyronitrile and 10 g of benzene.

Immediately after entering the second solution in the reactor, this is placed in a bath thermostatized at 70 ° C. Let t_ {0} be the moment in which the reactor content temperature reaches 70 ° C. Is left react.

At t0 + 30 hours, the reaction is stopped cooling the reactor contents as quickly as possible until room temperature (intermediate solution (S1)).

(S1) essentially comprises a copolymer of vinylidene chloride and methyl acrylate (intermediate polymer (P1)) as well as vinylidene chloride and methyl acrylate no converted into benzene solution.

The polymer (P1) comprised in the intermediate solution (S1) in methanol for 72 hours approximately, and then filtered and dried under vacuum in an oven (intermediate polymer (P'1)).

In a 25 ml glass reactor, they are introduced 6.01 g of styrene and 2.43 g of polymer (P'1). The empty.

The reactor is then placed in a bath thermostatized at 110 ° C. Let t_ {1} be the moment in which the reactor content temperature reaches 110 ° C. Is left react.

At t1 + 5 hours 45 min, the reaction is stopped cooling the reactor contents as quickly as possible until room temperature (solution-final mass (S2)).

(S2) essentially comprises a copolymer of blocks comprising a block of a chloride copolymer of vinylidene and methyl acrylate and a polystyrene block (block copolymer (P2)), as well as unconverted styrene.

From a sample of (S2), the distribution of the molecular masses of the block copolymer (P2) by steric solution chromatography.

The following results are obtained concerning the molecular mass distribution of (P2) M_ {n} = 2.0.10 <4>, M_ {z} = 4.3.10 <4>, and M_ {w} / M_ {n} = 1.58.

Claims (22)

1. Radical polymerization process for preparation of polymers of one or more chlorinated vinyl monomers, using

(TO)

one or several ethylenically unsaturated monomers, of which at minus one is selected from vinyl monomers chlorinated,

(B)

iodine molecular, and

(C)

one or several radical generating agents selected from among diazo compounds, peroxides and dialkyl diphenyl alkanes,

which comprises the stages according to which

(one)

be enter at least one fraction of each of the compounds (A), (B) and (C), and then

(2)

be reacts the contents of the reactor, introducing into it the same time the eventual rest of each of the compounds (A), (B) and (C),

until they have reacted:

-

how maximum 70 mol% of the chlorinated vinyl monomer (s) introduced into the reactor, if the monomer or ethylenically unsaturated introduced into the reactor are exclusively monomers chlorinated vinyl,

-

Y

-

how maximum 95 mol% of the chlorinated vinyl monomer (s) introduced into the reactor, if at least one ethylenically monomer unsaturated introduced into the reactor is a non-halogenated monomer, and stage (2) is then terminated.

2. Process according to claim 1, characterized in that at least 50 mol% of (A) are constituted by one or more ethylenically unsaturated monomers selected from the chlorinated vinyl monomers. 3. Process according to claim 1 or 2, characterized in that the one or one of the ethylenically unsaturated monomers is vinyl chloride. 4. Process according to claim 1 or 2, characterized in that the one or one of the ethylenically unsaturated monomers is vinylidene chloride. 5. Process according to claim 1, characterized in that (A) is constituted by a single ethylenically unsaturated monomer, which is a chlorinated vinyl monomer, at least 50 mol% of (A) being introduced into the reactor in step (1) . 6. Process according to claim 1, characterized in that (A) is constituted by several ethylenically unsaturated monomers, the ethylenically unsaturated monomers constituting (A) being introduced into the reactor in the same order of introduction. 7. Process according to claim 1, characterized in that (A) is constituted by several ethylenically unsaturated monomers, one of the ethylenically unsaturated monomers constituting (A) in step (1) being introduced into the reactor, the one or more being introduced into the reactor other ethylenically unsaturated monomers constituting (A) in step (2), as many times as the number of ethylenically unsaturated monomers constituting (A) minus 1, one after the other, any new introduction of an ethylenically unsaturated monomer being made in the reactor in step (2) only after the ethylenically unsaturated monomer (s) previously introduced into the reactor have each reacted in a proportion of at least 50 mol%. 8. Process according to claim 1, characterized in that (A) is constituted by several ethylenically unsaturated monomers, one of the ethylenically unsaturated monomers constituting (A) in step (1) being introduced into the reactor, introducing all or a fraction of the or of the other ethylenically unsaturated monomers constituting (A) progressively in the reactor in step (2). 9. Process according to any one of claims 1 to 8, characterized in that the number of moles of (B) referred to the number of moles of (A) is at least 2.5.10-5.

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10. Process according to any one of claims 1 to 9, characterized in that at least 50 mol% of (B) is introduced into the reactor in step (1). A process according to any one of claims 1 to 10, characterized in that the number of moles of (C) referred to the number of moles of (B) is at least 1. 12. Process according to any one of claims 1 to 11, characterized in that it is also introduced into the reactor in step (1) and / or in step (2),

(D)

one or several complexes of a metal, in the oxidation state 0 or in a strictly positive oxidation state, selected from among transition metals, lanthanides, actinides and metals of group IIIa, and of a ligand of this metal.

13. Process according to any one of claims 1 to 11, characterized in that the content of the reactor, in step (1) and in step (2), is free of complexes of a metal in the oxidation state 0 or in a strictly positive oxidation state, selected from transition metals, lanthanides, actinides and group IIIa metals, and from a ligand of this metal. 14. Radical polymerization process for preparation of block copolymers, at least one of whose blocks is a polymer block of one or more vinyl monomers chlorinated, using

(TO')

one or several ethylenically unsaturated monomers, and

(B ')

one or several polymers of one or more chlorinated vinyl monomers selected from the polymers prepared by the process according to any one of claims 1 to 13 and between the preparations in the course of a previous stage by the process claimed here according to the present claim 14,

which comprises the stages according to which

(one')

be introduces into a reactor at least a fraction of (A ') and at least one fraction of (B '), and then

(2')

be reacts the contents of the reactor, entering it into the same time the eventual remainder of (A ') and the eventual remainder of (B ').

15. Polymers of one or more chlorinated vinyl monomers, characterized in that they have a number average molecular mass M_ {n} greater than 1.0.10 <4> and a ratio M_ {z} / M_ {w} less than 1, 65 16. Polymers according to claim 15, characterized in that they are polymers of vinyl chloride and have a polydispersity index M w / M n of less than 1.60. 17. Polymers according to claim 15 or 16, characterized in that they have a whiteness measured by the MINOLTA® CR 200 chromimeter, which has a value of at least 80%. 18. Block copolymers comprising the minus a polymer block of one or more vinyl monomers chlorinated according to any one of claims 15 to 17. 19. Block copolymers comprising the minus a polymer block of one or more vinyl monomers chlorinated, which have a number average molecular mass M_ {n} greater than 1.5.10 4 and a polydispersity index M_ {w} / M_ {n} less than 1.60. 20. Items manufactured using one or more polymers selected from the polymers prepared by the processes according to any one of claims 1 to 14, and the polymers according to any one of claims 15 to 19. 21. Use of molecular iodine in a process of radical polymerization to prepare polymers of one or more chlorinated vinyl monomers, using one or more monomers ethylenically unsaturated of which at least one is selected between the chlorinated vinyl monomers and one or more agents radical generators selected from the diazo compounds, peroxides and dialkyl diphenylalkanes, according to which the polymerization process radical comprises the following stages:

-

be at least one fraction of molecular iodine is introduced into a reactor, at minus a fraction of the ethylenically monomer (s) unsaturated and at least a fraction of the generating agent (s) of radicals, and then

-

be reacts the contents of the reactor, introducing into it the at the same time the eventual rest of molecular iodine, of the or ethylenically unsaturated monomers and of the agent (s) radical generators,

until they have reacted:

-

how maximum 70 mol% of the chlorinated vinyl monomer (s) introduced into the reactor, if the monomer or ethylenically unsaturated introduced into the reactor are exclusively monomers chlorinated vinyl, and

-

how maximum 95 mol% of the chlorinated vinyl monomer (s) introduced into the reactor, if at least one ethylenically monomer unsaturated introduced into the reactor is a non-halogenated monomer, and then the reaction ends,

to confer a living character to that process of radical polymerization. 22. Use of molecular iodine in a process of radical polymerization that uses one or more monomers ethylenically unsaturated of which at least one is selected between the chlorinated vinyl monomers and one or more agents radical generators selected from the diazo compounds, peroxides and dialkyl diphenylalkanes, according to which the polymerization process radical comprises the following stages:

-

be introduces into a reactor at least a fraction of molecular iodine, at minus a fraction of the ethylenically monomer (s) unsaturated and at least a fraction of the generating agent (s) of radicals, and then

-

be reacts the contents of the reactor, introducing into it the at the same time the eventual rest of molecular iodine, of the or ethylenically unsaturated monomers and of the agent (s) radical generators,

to prepare polymers of one or more monomers chlorinated vinyl whose growth of polymer chains can restart by reacting these polymers again, eventually after being isolated from their means of polymerization, with ethylenically unsaturated monomers, identical or different from those that had been previously polymerized.